1. Building Foundations

2. Foundations
The foundation of a building transfers the weight of the building to the ground.
Normally, every building has a number of individual foundations, commonly called “footings”.
Usually each column of the building will have its own footing.

3. Soil Bearing Capacity
Since the weight of the building rests on the soil, engineers must study the properties of the soil very carefully to ensure it can carry the load (weight) of the building
To properly support a building, the soil must be firm and strong.
It is common for the soil near the surface of the earth to be loose and weak.
If a building is rested on this soil, it will sink.

4. Types of Foundations 2 Categories: Shallow and Deep Shallow
Can be made in depths of as little as 3 feet
Used for small, light buildings
Deep
Can be made at depths of feet
Used for large, heavy buildings

5. Shallow Foundations: Individual Footings
Individual footings are one of the most simple and common types of foundations.
Used when the load of the building is carried by columns
Each column will have its own square of rectangular pad of concrete on which it will sit.

6. Shallow Foundations: Strip Footing
Commonly found in load-bearing masonry construction, and act as a long strip that supports the weight of an entire wall.
Used when loads are carried by an entire wall, instead of isolated columns.

7. Shallow Foundations: Raft or Mat Foundation
Used most often when basements are to be constructed.
The weight of the building is spread evenly over the entire footprint of the building.
Used where the soil is weak, and where loads have to be spread out over a large area

8. Deep Foundations: Pile Foundations
A pile is a long cylinder of a strong material that is pushed deep into the ground so the structures can be supported on top of it
Used when there is a layer of weak soil at the surface, or when a building has very heavy concentrated loads, such as a high rise
2 Types: End-bearing, and Friction
End-bearing piles: the bottom end of the pile rests on a layer of strong soil or rock
Friction piles: the pile transfers the load across the full height of the pile, by friction, and works to transfer the forces to the soil

9. What are piles made of? Piles can be made of wood, concrete, or steel.

10. How are piles used?
As pile foundations carry a lot of load, they must be placed to ensure the soil is not overloaded beyond its bearing capacity.

11. How are piles put into place?
Piles are first cast at ground level, then hammered or driven into the ground using a “pile driver”.
The pile driver lifts and holds the pile perfectly vertical, then hammers it into the ground blow by blow until it cannot be driven any further into the soil.

12. Helical Pile
Helical piles are steel tubes that have helical (spiral) blades attached to them.
They can be drilled into the ground from above
Once the pile is driven into the ground, a pile cap is poured on top to prepare it for construction above.

13. Sources Understand Construction